Sending mechanism for pneumatic-despatch apparatus.



H. 1). WATER HOUSE. V SENDING MECHANISM FOR PNEUMATIC DESPATOHAPPARATUS.

I V APPLIUAIION FILED D30. 2, 1907. 974,618.

Patented Nov 1, 1910.

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nnr i HAROLD D. WATER-HOTTSE, 0F QUINCY, MASSACHUSETTS, ASSIGNOR, BYMESNE AS- SIGNMENTS, TO AMERICAN PNEUMATIC SERVICE COMEANY, OF BOSTON,MASSA- GI-IUSETTS, A CORPORATION OF DELAWARE.

SENDING MECHANISM FOR PNEUMATIG-DESPATCH APPARATUS.

ow ers.

To all whom it may concern;

Be it known that "I, HAROLD D. WATER- HoUsn, citizen of the UnitedStates, residing at Norfolk Downs, Quincy, in the county of Norfolk andState of Massachusetts, have invented certain new and usefulImprovements in Sending Mechanism for Pneumatic-Despatch Apparatus; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

The invention relates to sending apparatus for pneumatic despatchsystems, and more especially to sending apparatus adapted to be used forsending comparatively large and heavy carriers such as are commonlyemployed for transmitting mail and other heavy matter.

The objectof the invention is to provide an improved construction ofsending mechanism which will enable the carriers to be despatched inrapid succession and at proper intervals without undue loss of air fromthe transmission tube, and without requiring any attention on the partof the operator other than to place the carriers successively inposition to be delivered to the transmission tube.

The apparatus embodying the various features of the invention comprisesa sending chamber through which the carriers are introduced into thetransmission tube, and inner and outer gates for closing the sendingchamber which are so controlled and operated that the outer gate isautomatically closed behind the carrier immediately after the carrierenters the chamber, while the inner gate is automatically opened afterthe carrier has entered the sending chamber to allow the carrier to passfrom the sending chamber into the transmission tube, and thenautomatically closes to cut off communication between the sendingchamber and the transmission tube preparatory to the sending of a secondcarrier;

One of the principal features of the invention consists in providingmeans for counterbalancing the pressures on opposite sides of the innergate, so that said gate may open under the action of the carrier as itslides through-the sending chamber. By reason of the counterbalancing ofthe pres- Specification of Letters Patent.

Application filed December 2, 1907.

Patented Nov. 1, 1910.

Serial No. 404,806.

sures on opposite sides of the inner gate, carriers may be inserted andtransmitted withoutregard to the presence or absence of pressure withinthe sending chamber, and the delay incident to the equalizing of thepressure on opposite sides of this gate by the flow of air through arestricted bypass is avoided. The construction is also simplified, andthe action of the apparatus rendered more reliable, by the eliminationof devices for controlling the equalizing flow of air from the inner tothe outer side of the inner gate. The presence of devices operated bythe carrier for causing the equalization of the pressures in the transittube and sending chamber, in order that the inner gate may be opened bythe carrier, is also avoided. This feature of the invention may beembodied in constructions in which a pressure substantially equal to thepressure in the transmission pipe is normally maintained within thesending chamber, or in constructions in which the pressure within thesending chamber is normally atmospheric, the devices for operating andcontrolling the operation of the outer gate being modified to suit theconditions under which this counterbalancing feature is employed.

Further features of the invention relate more or less to theconstruction and arrangement of parts which it is preferred to employ inembodying the principal feature of the invention in a simple andreliable construction, and while these features are not essential to thebroad scope of the invention, they are of importance in contributing tothe simplicity and efficiency of the apparatus.

The various features of the invention will be understood from aninspection of the accompanying drawings, in which- Figure 1 is avertical sectional view of a transmitting mechanism embodying thefeatures of the invention in the form in which I prefer to employ them;Fig. 2 is a detail of the timing mechanism for controlling the sendingof successive carriers, and Fig. 3 is a detail showing a modified formof means for counterbalancing the pressure on opposite sides of theinner gate.

In the construction shown in Fig. 1, the sending chamber 1 is arrangedin l1ne with and forms in effect a continuation of the transmission tube2. The transmission tube is in open communication with the supply pipe 3through the slots 4 formed in the wall of the transmission tube. Theinner or lower end of the sending chamber is normally closed by an innergate or valve 5, which is pivoted at 6, and is normally held in closedposition by the weight of the parts connected with it. The valve or gateis arranged to swing within a chamber 7 located between the lower end ofthe sending chamber and the communication between the supply pipe andthe transmission pipe, so that the opening and closing of the gate 5does not affect the. flow of air from the supply pipe to thetransmission pipe. The chamber 7 is provided with. a lateral opening 8lead ing to a second chamber 9 which is in constant communication withthe sending chamber 1 through an opening 10. Communication between the.chambers 8 and 9 is closed by means of a plate or diaphragm 11 which issecured to the supporting arm 12 which carries the gate 5. In, theconstruction shown in Fig. 1 this plate or diaphragm. 11 engages a seat18.surrou1 idn1g the opening 8 when the gate 5. is in closed position.Then the gate. 5 is in closed position the under side of the diaphragm11 is: subjected to the pressure within the transn'iission pipe, and thearea of theplate is such that the pressure on the. plate approximatelycounterbalances the pressure on the inner side of the gate 5. The tppersijcle of the plate 11 is subjected to. whatever pressure is. withinthe sending chamber, and. this pressure approximately counterbalancesthe pressure. on the outer side of the gate 5. The pressures on oppositesides of the inner gate are therefore substantially counterbalanced sothat the opening and closing. ot the. gate is substantially unaffected:by the pressures on opposite sides of the gate. The. gate. may beweighted, therefore, in. such manner that it will readily open whenengaged: by the carrier as. it slides through. the transmission chamber,and will quickly return. to. closed position. after the carrier haspassed from the sending. chamber to, the transmission tube. When theinner gate opens, compressed air from the transmission. tube willenterthe lower endof the sending chamber, so that the pressure withinthe sending. chamber will become the same as it is within thetransmission tube. In case the diaphragm 11 does not fit closely withinthe chamber 9, a. part of the air enteringthe sending. chamber may passthrough the openings and chamber 9-. Such flow of air is. functionless,however, as the gate. 5 is at this. time. open, and there is freecommuni cation between the sending chamber and:

transmission tube.

Instead. of constructing the. plate on diaphragm which. is. subjected.on opposite sides. tot-he pressureson. opposite sides of the gatev 5 asshown in Fig. 1, this plate or diaphragm may be constructed as indicatedin Fig. 3. As here shown, a diaphragm 11 is secured to the gate 5, andis arranged to fit closely within a segmental chamber 9, the curved wallof which is concentric with the axis about which the gate 5 swings. Inthis construction the diaphragm ll closes the opening 8 between thechamber 7 and the chamber 9 when the gate 5 is closed, and thisdiaphragm is subjected on opposite sides to the pressures on oppositesides of the gate as in the construction shown in. Fig. 1. hen the gate5. opens, the diaphragm 11 swings upward within the chamber 9, the outeredge. of the diaphragm remaining in contact with the curved wall of thechamber andcontinuing to cut off communication between the chamber 9 andthe chamber 7. This construction operates upon the same principle asthat shown in Fig. 1, and may be employed with advantage, although theconstruction shown in Fig. 1 is preferred, since it operates with lessfriction, and since the parts may be more conveniently and cheaplyconstructed and adjusted.

Other constructions and arrangements of devices for counterbalancing thepressures on opposite. sides of the inner gate may be employed inpracticing the broader features of the invention.

The upper or outer end of the sending chamber is provided with an outergate let which is pivoted at 15 and is normally held in position toclose the upper end of the sending chamber by means of a weight 16. Thisgate is normally locked in closed position by means of a latch 17arranged to engage the lower edge of' the gate and to be disengagedtherefrom by the carrier as it slides down against the gate.

VVhenav carrier is to be transmitted, it is placed within an inclinedreceiving chute 1 8' which is arranged in line with the. sendingchamber, and: when so placed, slides down over the latch 17 and againstthe outer gate 14. In the construction shown, the pressure within thesending chamber is normally atmospheric, and. thereforethe gate 14L-isfree to open under the weight of the carrier which slides down into thesending chamber.

The gate 145 immediately closes behind the carrier, and: the carrierslides down against the gate 5. Since the pressures on opposite sides ofthe gate 5 are substantially counterbalanced, the weight of the carrieris suiiicient to open the gate and the carrier slides down into thetransmission tube, the gate 5 immediately closing behind it.

In order that a sufficient intervals may elapse between the entrance ofsuccessive carriers intothe sending chamber to enable the first carriertov pass from. the. sending chamber into. the transmission tube. beforethe succeeding carrier opens the. outer gate,

a timing device is provided for controlling the'sending; of successivecarriers. In the construction shown, this timing mechanism comprises astop'19 pivotally mounted above the chute 18 some distance beyond orabove the outer gate 14. This stop is connected by a rod 20' to adiaphragm 21 mounted within a diaphragm chamber 22, and is held normallyout of the path of the carrier by a spring 23 acting against the underside of the diaphragm. The chamber above the diaphragm communicatesthrough a pipe 24. with the chamber 9, which is in constantcommunication with the sending chamber. The diaphragm chamber alsocommunicates with. the atmosphere through a vent which may be adjustedby a needle valve 26. When the inner gate 5 opens and. the pressurefromv the transmission pipe enters the sending chamber and chamber 9,this pressure is transmitted through the pipe 24 to the upper side ofthe diaphragm 21, forcing the carrier stop 19 forward into the path ofthe carrier, so that the entrance of a second carrier into the sendingchamber is prevented until the carrier stop is removed from the path ofthe carrier. The compressed air within the sending chamber graduallyleaks out into the atmosphere through the vent 25 after the carrier haspassed from the sending chamber and the gate 5 is closed. As thepressure above the diaphragm decreases, the spring 23 forces back thediaphragm, withdrawing the carrier stop. As soon as the carrier stop hasbeen withdrawn, a second carrier may be transmitted, since the pressurewithin the chamber 1 has fallen to substantially atmospheric pressure,and the opening of the outer gate 14 is not prevented by the pressureWithin the chamber.

lVhile it is preferred to connect the timing mechanism and the timingstop with the sending chamber, and to provide a vent from the sendingchamber to the atmosphere, so that the pressure within the sendingchamber will be normally atmospheric, this construction is not essentialto the broader features of the invention, and may be varied withoutdeparting from the broad scope of the invention.

Having explained the nature and object of the invention, andspecifically described forms of apparatus in which it may be embodied,what I claim is 1. In a pneumatic despatch system, a transmission tube,a sending chamber, inner and outer gates for closing the sendingchamber, means for closing the outer gate after a carrier has enteredthe sending chamber, means for counterbalancing the pressures onopposite sides of the inner gate, and a supply pipe having acommunication with the transmission tube unafiected by the opening andclosing of the inner gate, sub stantially as described.

2. In a pneumatic despatch system, a transmission tube, a sendingchamber through which the carrier slides, inner and outer gates forclosing the sendmg chamber mounted to open under the pressure of aninserted carrier, means for closing the gates when the carrier haspassed, means for counterbalancing the pressures on opposite sides ofthe innervalve, and a supply pipe having a communication with thetransmission tube unafiected by the opening and closing of the innergate, substantially as described.

3. In a pneumatic despatch system, a transmission tube, an inclinedsending chamber through which the carriers slide, inner and outer gatesmounted to open under the pressure of an inserted carrier, means forclosing the gates after a carrier has passed, means for counterbalancingthe pressures on opposite sides of the inner gate, and acarrier-receiving chute in line with the sending chamber, substantiallyas described.

4. In a pneumatic despatch system, a transmission tube, a sendingchamber through which the carriers pass to the transmission tube, innerand outer gates mounted to open under the pressure of an insertedcarrier, means for closing the gates after a carrier has passed, meansfor counterbalancing the pressures on opposite sides of the inner gate,and means for controlling the entrance of successive carriers into thesending chamber, substantially as described.

5. In a pneumatic despatch system, a transmission tube, a sendingchamber through which the carriers pass to the transmission tube, innerand outer gates mounted to open under the pressure of an insertedcarrier, means for closing the gates after a carrier has passed, meansfor counterbalancing the pressures on opposite sides of the inner gate,and means controlled by the carrier for locking the outer gate,substantially as described.

6. In a pneumatic despatch system, a transmission tube, a sendingchamber through which the carriers pass to the transmission tube, innerand outer gates mounted to open under the pressure of an insertedcarrier, means for closing the gates after a carrier has passed, meansfor counterbalancing the pressures on opposite sides of the inner gate,a stop for preventing the entrance of the carrier into the sendingchamber and a timing mechanism rendered active by the passage of acarrier through the sending chamber for withdrawing said stop,substantially as described.

7 In a pneumatic despatch system, a transmission tube, a supply pipecommunieating therewith, a sending chamber, a valve chamber between thesending chamber and the communication between the supply pipe andtransmission tube and provided with a lateral opening, a chamber incommunication with the sending chamber, a valve in the chamber normallyclosing the sending chamber, and a diaphragm connected with the valveand closing the opening between the valve chamber and the chamber whichis in communication with the sending chamber, substantially asdescribed.

8. In a pneumatic despatch system, a sending chamber, an outer gatetherefor, means for closing the outer gate after a carrier has passed, apivoted inner gate, and a diaphragm connected to swing with the gate andsubjected on opposite sides to the respective pressures on oppositesides of the inner gate, substantially as described.

9. In a pneumatic despatch system, a sending chamber, an outer gatetherefor, an inner gate, a pivoted arm carrying the inner gate, and adiaphragm carried by the arm and subjected on opposite sides to therespective pressures on opposite sides of the inner gate, substantiallyas described.

10. In a pneumatic despatch system, a sending chamber, an outer gatetherefor, a

pivoted inner gate, a counterbalancing plate connected with the innergate and subjected on opposite sides to the respective pressures onopposite sides of the inner gate, a transmission tube, and an air supplytherefor unaflected by the opening and closing of the inner gate,substantially as described.

11. In a pneumatic despatch system, a sending chamber, an inner gatetherefor, a pivoted arm carrying said gate, a plate secured to said arm,a chamber below the gate in communication with the transmission tube,and provided with a lateral opening closed by the plate, and a chamberon the opposite side of said plate in communication with the sendingchamber, substantially as described.

In testimony whereof I afiix my signature, in presence of two witnesses.

HAROLD D. WATERHOUSE.

Witnesses:

IRA L. FISH, ANNIE C. RICHARDSON.

